Being immunodeficient is annoying when it comes to vaccines - I can only have the dead ones, and there is no guarantee that the vaccine will "take" and provide me any coverage or if it does, what level of coverage.
However, as long as it does not cause problems, I go for the vaccine where possible.
Better safe than sorry!
Hep B and C vaccines won't start providing coverage until the full vaccine cycle is complete anyway, so I would wait until then to draw conclusions about the efficacy no matter which other drugs you are on.